<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>02_边框与内间距</title>
  <style>
    .d1 {
      width: 200px;
      height: 200px;
      background-color: #0aa1ed;
      border: 5px solid red;
      border-top: 5px dashed green;
      border-radius: 10px;
    }
    .d2 {
      width: 200px;
      height: 60px;
      background-color: #0aa1ed;
      /*border: 5px solid red;*/
      /*border-top: 5px dashed green;*/
      border-radius: 30px;
    }
    .d3 {
      width: 200px;
      height: 60px;
      background-color: #0aa1ed;
      /*border: 5px solid red;*/
      /*border-top: 5px dashed green;*/
      border-radius: 100px/30px;
    }
    .d4 {
      width: 200px;
      height: 200px;
      background-color: lightcoral;
      padding-left: 50px;
      /*padding: 0px 0px 0px 50px;*/
      margin: 50px;
    /*  预设尺寸内*/
      box-sizing: border-box;
    }
    span {
      background-color: red;
    }
    .s2 {
      background-color: rgba(255,0,0,.3);
      padding: 50px;
    }

  </style>
</head>
<body>
<span>span1</span><span class="s2">span2</span><span>span3</span>
<div class="d1"></div>
<div class="d2"></div>
<div class="d3"></div>
<div class="d4"></div>

</body>
</html>